Nope. I dont see a way to do it in *NIX land or other OS from my
experience. The system(s) has(have) to be "secured" before the docs
created/composed on the system can be "secure".
The local sysadmin can arrange for local access to memory, and can trojan
any application. SSH does *nothing* for securing a host. The only thing
that SSH tries to do is to "provide a more secure connection across an
insecure network." The assumption is that you have both hosts secured from
outsiders. Either host being comprimised means increased risk to the other
machine.